I faced I few videos which show clicks after setting PRE on, and RFG to 0+ and than increasing Audio Gain to 20+. There is significant distortion in ouput audio like overloading audio frequency amplifier.
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Hi Yuri,
Interesting, I had the pre-amplifier enabled and the rf-gain set to 0 (default setting) but didn’t hear distortions. Do you have a link of such video that shows this behavior?
73 Stephan
I will add links a little bit later when arrive at home.
Here are a few videos:
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Hi Yury,
Thanks for providing these two videos!
In the first video, one hears a lot of man-made RF noise, and after Vlad connects the line output to an external (active) speaker, suddenly a French voice can be heard. But I’m not sure what was the problem that Vlad wanted to show. IMHO, a signal generator would be better and more repeatable to analyze a problematic RX behavior.
In the second video, I focused on the SSB part, but even after listening and looking at the transceiver’s display (for changing AGC, AF- and RF-gain values), I’m not sure if I really understood the problem.
Using the translator, it seems that there is a problem with AGC and therefore overloading the AF-stage. Further, it seems that part of it can be solved by increasing the RF-gain, but this sound not logic to me and I’m not sure if I understood it correctly. Unfortunately, due to the not perfect English translation (that is moreover not my mother tongue), I may have missed the fine details.
I really appreciate that RX3ALL sent his findings to the developers, so we may hope for an improvement in this weak spot.
I can only compare the TX-500 with my FT-818 in the field. At home, using my IC-7300 is useless, due to high level of man-made noise.
As of now, I’m very happy with the reception performance of this transceiver, also thanks to the diverse filter setting possibilities. But I’ll have to further tweak and play with it in the field. Time and future firmware updates will tell.
73 Stephan
Thank you, Stephan
I add little bit more context at the evening.
Here is video, where RX3ALL connects RF Generator to Xiegu G90 and TX-500.
As a result sensitivity of TX-500 meets the specs but at some time there are noticeable distortion during receiving signal from generator at 3:50m.
Also Vlad posted video for TX-500 where he set equalizer to 5 or 10 for SSB and this solved annoying noise (clicks). You cat try to do this (increase EQL RX HF to 100) on your rig and enable PRE and RFG to 5, I am very curious about results.
I’m diving to this due to fact that I recently sold my Xiegu G90 due annoying hiss noise. I was not able to work with G90 more than 15 minutes without break using headphones. Here is comparision of audio noise with my home brew superhet trx (please, use headphones or increase volume):
That is why I would like to make sure that TX-500 does not have similar problems like G90.
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Hi Yury,
I can’t say much about the first video, since I have no experience with CW. The filter is set to 50Hz, which is very narrow.
In the second video: at which time can the problematic behavior heard?
About comparing your home-brew radio with the G90 in the third video: I could not hear hiss with the G90, but maybe I misunderstand/misinterpret this term.
The G90 definitely lacks some bass but has more treble than your home-brew rig that lacks the higher frequencies. It sounds to muffled to me, but this is very personal.
I have no idea about the filter settings in both radios, but the slope of the flanks (I hope this is the correct English term) will be anyways very different for both radios. To have a fair comparison of the sound, both TRXs should at least use the same speaker.
73 Stephan
The audio level was set higher on the G90 than the SW2017 and we are talking different loud speaker sizes as well I believe. Again, it’s not clear what is thought to be the problem but I have no such problem with my G90 - perhaps because I normally operate with headphones?
I remember my old FT817ND was difficult to listen to at high volume levels until I changed the speaker from the original Yaesu one to one that was the same impedance and size but that was with a plastic (Mylar?) radiator rather than a cardboard/paper one. The replacement was actually built for model railway systems.
In any case the G90 and FT817 are getting off topic here from the TX500’s (apparent) problems. As always what is a problem for one operator might not be so for a different person.
73 Ed.
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To finally close off topic, on 0:35 on my G90 video I hear strong hiss noise despite the fact that it was spring near the lake without any man-made or atmosphere static noise. The audio gain was not important because using headphones or line-in for recording produce the similar result with hiss noise only from G90
I also constantly use high-impedance headphone and It was hard to use it with G90 after QCX or 2017 or FT-891.
Unfortunately, I sold G90 and was not able to record using audio input like here in video:
But anyway, I agree with you about
what is a problem for one operator might not be so for a different person
Let’s continue to discuss TX500 =)
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I just put my Sennheiser headphones on and listened carefully once more: the recording sounds very good to me and as you said it seems Spring with all the birds singing. But I still can’t hear any hiss at this 0:35 position, to me it’s simply loud noise, just before the AGC kicks in.
And as Ed @DD5LP already said, these things are very subjective.
73 Stephan
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Hi all, I don’t have any experience of any of these radios, but I’ve been following this discussion with interest
It seems fairly clear to me that you are actually both talking about the same thing 
. Even without possible language differences and so on, “hiss” and “noise” are much the same thing, from my perspective…
As I say, I’m not familiar with these radios, but it sounds to me like the G90 has much higher RF gain, combined with fast AGC - if it has a RF gain control, winding it back would drastically reduce the burst of noise/hiss. Actually, I think i read something along these lines on a review on eHam.net. Possibly a firmware update was needed to give this control though. I know this is off topic, but but couldn’t resist adding my opinion. Sorry!
I’d also like to say that I’m very impressed with your homebrew transceiver, Yury. Very professional looking!
73
Steven
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Sometimes you don’t know where the hiss/noise is coming from, but if it is an SSB receiver, the filter will have cut off signals from the signal frequency that are more than say, 3 khz. So if your headphones have high frequency hiss, it’s just as likely to be from the AF stage as the IF. And not coming from the signals hitting the antenna at all. I had this problem with an IC701 I used some time ago, with Sennheiser headphones that were very wide range. At that time I was young enough to hear at least to 15 khz (tvs drove me mad). And the audio stage in the 701 made enough noise at high audio frequencies to make those headphones quite uncomfortable for long periods of use.
A filter at audio frequencies sorts that out of course, but you shouldn’t need to go to such lengths. I wonder if anyone has tried that with the tx500.
Andrew VK1DA/VK2UH
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This is what I think as well.
At this 0:35 position, the G90 was just switched on, probably having max. RF-gain, until the AGC kicked in.
73 Stephan
This can be easily achieved with the TX-500: go to the RX-AF equalizer settings, and turn down the higher frequencies.
Or go to the currently selected filter settings and limit the upper frequency, let’s say to 2000Hz.
I tried both settings just now. If you like muffled sound, you can easily get that.
73 Stephan
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That is a good solution provided the amplifiers after the filter are either super quiet or have their own filtering. In the case of the IC701, I think the audio amp chip was quite noisy across the whole audio spectrum. You hear nothing on your ordinary speaker, but in hi fi headphones you hear it all. The filter in the low level audio stages has no impact on this noise.
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Nope,
This is problem with AGC in G90 (firmware). If I turn off AGC it will be a little bit noisy than sw2017 but enabled AGC adds significant amount of noise.
To be honest, RF Gain was set to minimum value 1% on Xiegu G90 in the video.
You can also notice that Xiegu G90 S-meter reports something about S7 but mini sw2017 S-meter shows something about S9+15 when the same OP say hello. This means that sensitivity of sw2017 is better than G90. And this is not a QRN or signal level changes.
G90 is a little noisy and a little deaf transceiver, this is pity but true. You can check Receiver Test Data list there G90 is in the bottom of the list for receiver Sensitivity.
My DIY mini sw2017 has sensitivity about 0.35uV comparing with G90 with 1.0uV when RF Gain set 50%. With RF Gain 1% G90 Sensitivity will be worse.
Such hiss noise is common problem of Xiegu products, read comments here:
The new Xiegu X6100 portable HF transceiver: Yes, it’s real and no it’s not vaporware | Q R P e r
Part of them contains info about hissy noise for X5105 and G90.
I also very long used G90 (about a year) and after 10-15 minutes got tired by audio noise even during very noise quiet evenings. I was bribed by the rich functionality of G90, but it was impossible to use G90 with headphones which my main user case.
The only strong point of Xiegu G90 is price =)
But anyway, I just shared my experience with Xiegu G90 (deaf, buggy firmware, noisy audio), but it just personal preferences. Someone can say that it’s valuable transceiver for it price. May be, but not for me, I am happy that sold it.
I’d also like to say that I’m very impressed with your homebrew transceiver, Yury. Very professional looking!
VK2STG, thank you. But this transceiver is designed/developed by UR3LMZ and VERY popular in back USSR countries due to good specs for portable use (some more info herehttps://www.qrz.com/db/EW1AEI). I am only some kind of kit builder/improver.
Now, say everything about G90 and would like to stop off-topic from my side.
Hi Andrew,
I didn’t test the TX-500 with Hi-Fi headphones, since I’ll never take them with me to a summit 
but I just tried it at home with my not too bad in-ear headphones and a compromised antenna with typical human-made noise in the city.
Of course, one can hear noise, (probably) also from the AF amplifier when cranking up the volume (it can deliver up to 3W AF output power!), but as soon you plug in the antenna, the noise gets much stronger.
Also when maxing the volume without connecting the antenna, the filters and the equalizer allow to mute the higher frequencies, which shows that this noise mainly origins from before the AF amplifier.
To me it’s all in the expected and normal range. So if one doesn’t like the high noise that you call “hiss”, just reduce the higher frequency response, as some of us did ages ago when playing a tape that was recorded with Dolby NR/B 
.
73 Stephan
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This also can be achieved by soldering 22-47nF capacitor from input audio amplifier to ground in some rigs like FT-817 or FT-857 or any where you have. This mod cuts high part of audio frequencies in the same way as equalizer does in TX-500.
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Hi Yury,
You have a lot of experience with the G90, and you even improved it with several mods (as seen on your QRZ page), so I think you had good reasons to sell it at the end. It simply didn’t fulfill your expectations in some fields.
Firmware that is closed-source and not maintained by the selling company is a pain…, it basically voids the value of the hardware. Until now, Lab599 was very good in this respect, but time will tell.
BTW: I’m amazed by Icom lately, by how much energy they put in maintaining their firmware.
I don’t own and never used any Xiegu transceiver, so I’m not the right person to discuss about it.
My point was simply by observation of the shown behavior: you switched the device on and it produced a lot of noise/hiss initially, while it was probably still in the boot process and not necessarily yet applying all the parameters correctly (e.g. the RF-gain). Moments later, to me, it seemed the AGC kicked in and it behaved properly.
Difficult to judge from a few seconds video.
Also, this sw2017 seems a very interesting and capable transceiver, as far as I can judge from the videos.
Back to the topic: if you’re interested in the TX-500, the best would be if you could join somebody in your vicinity and test this rig yourself, before buying it. But realistically, this might be problematic, as many hams are still waiting for it. Since I ordered and payed it, I waited for about one year to get it finally delivered from Sweden.
73 Stephan
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Stephan, Thank you!
if you’re interested in the TX-500, the best would be if you could join somebody in your vicinity and test this rig yourself, before buying it.
It seems to me the best variant.
Due to fact that I sold most of my RIGs (G90, some yeasu) and left only DIY ones like mini sw2017, QCX, etc I am looking for good portable RIG with reach set of features (at least current use, different filters, NB, DNR, etc).
There are few candidates like:
- TX500 - very like it, best candidate for now, that is why so much attention to it from my side
- FT-891 - very like receiver and overall, but a little bit heavy and 1A on RX requires big battery
- KX2 - also like, but expensive and hard to order in my QTH
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